The invention relates to a surfactant package and a water-in-hydrocarbon emulsion using same.
The incorporation of water into hydrocarbons is useful for various purposes including the provision of fuels having desirable properties.
Attempts to provide water-in-hydrocarbon emulsions have met with very serious technical and economic problems due to short-term stability of emulsions formed having droplet sizes in the macroemulsion range, and further due to the large quantities of surfactants and cosolvents required to form emulsions having droplet sizes in the microemulsion range.
For example, U.S. Pat. Nos. 4,568,354 and 4,568,355 to Davis et al. are drawn to processes for converting a hazy or potentially hazy water saturated alcohol-gasoline mixture into a clear stable gasoline composition having an improved octane rating. The system so produced has a water content of no more than 1% by volume, and relatively large volumes of non-ionic surfactant are used to produce this system.
Similarly, U.S. Pat. Nos. 4,770,670 and 4,744,796 to Hazbun et al. also disclose the formation of stable microemulsions which contain large amounts of surfactant as compared to the water content.
Other efforts in this area include U.S. Pat. No. 5,104,418, WO 99/35215, U.S. Pat. No. Re. 35,237, U.S. Pat. No. 5,743,922, WO 97/34969, U.S. Pat. No. 5,873,916 and WO 99/13031.
In spite of the disclosures in the a foregoing patents, the need remains for a water-in-hydrocarbon emulsion which is stable and which contains a desirable amount of water without the need for relatively large amounts of surfactant and/or other stabilizing agents.
It is therefore the primary object of the present invention to provide water-in-hydrocarbon emulsions which are both stable and formed using relatively small amounts of surfactant.
It is a further object of the present invention to provide a surfactant package which is useful for providing such water-in-hydrocarbon emulsions.
Other objects and advantages of the present invention will be readily apparent from a consideration of the following.